package com.example.filter;


import com.alibaba.fastjson.JSON;
import com.example.common.BaseContext;
import com.example.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @ClassName: LoginCheckFilter
 * @Description: 检查用户是否已经完成登录
 * @author: 名字
 * @date: 2022/5/10  15:57
 */
@WebFilter(filterName = "LoginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER=new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request=(HttpServletRequest) servletRequest;
        HttpServletResponse response=(HttpServletResponse) servletResponse;

//        1、获取本次请求的URI
        String requestURI = request.getRequestURI();

        log.info("拦截到请求：{}",requestURI);

//        定义不需要处理的请求路径
        String[] urls=new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**"

        };
//        2、判断本次请求是否需要处理
        boolean check = check(urls, requestURI);
//        3、如果不需要处理，则直接放行
        if(check){
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request,response);
            return;
        }
//        4、判断登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("employee")!=null){
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("employee"));

            Long empId= (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);
            filterChain.doFilter(request,response);
            return;
        }
        log.info("用户未登录");
//        5、如果未登录则返回未登录结果,通过输出流向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }
    //路径匹配，检查本次请求是否需要放行
    public boolean check(String[] urls,String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if(match==true){
                return true;
            }
        }
        return  false;
    }
}

